Timing device



Amis 25, 1944.l

F. J. HQovEN TIMING DEVICE Filed July 22, 1939 2 Sheets-Sheet 2 atente`d pre 25, zi

iiii

2,34*?,dti

TWG @MCE Frederich il. Hloevw, ldaytcn, @his Application July 22, M39, Serial No.. 2%908 16 Claims. (Cl. IVW-330) lThis invention relates to timing devices and more particularly to devices for establishing electrically a series of periodic impulses adapted for the control of aperiodically recurrent function.

It is a principal object of the invention to provide a timing device which is simple in construction and operation, light in weight, and which provides for establishing accurate, uniform and predetermined time intervals.

Itis a further object to provide such a device in which the time intervals are controllable over a wide range with simplicity and accuracy. Et is also an object to provide a device oi this character for producing a series of timed impulses adapted :for the control of a periodically recurrent function where both the time between the impulses and the actual duration of the impulses are predetermined and controllable.

Et is a further object to provide a control device for use with a bomb rack for eiecting the rapid sequential release of a plurality of bombs at uniform time intervals apart and at a desired frequency, and in predetermined number as de termined by the operator. Y

@ther objects and advantages will be apparent from the following description, the accompanying drawings, and the appended claims.

In the drawings- Fig. i shows schematically a simple timing arrangement for securing periodic operation at predetermined time intervals of a plurality oi relays;

Fig. 2 is a diagrammatic representation of a similar circuit incorporating a control circuit and a frequency multiplying control; and

Fig. 3 is a diagrammatic showing of a complete system as arranged for the sequential release of a plurality of bombs.

in accordance with the present invention a timing device is provided which is' adapted to eiect the generation of a series of periodic timed impulses, the impulses being of predetermined duration, and at properly spaced uniform intervals. Such series of impulses may be utilized for the control of a periodically recurrent function, where such, timed sequence of operations is desired, for effecting suitable operation of a device. Since the invention provides for producing a series of impulses electrically and with extremely simple apparatus, and embodies very simple and readily operable means for the control of the timing period thereof, the device is highly useful Where simplicity, reliability'and low weight are important factors. l

A preferred iield of application of the device is for the control of the droppin@r of a plurality of bombs from an aircraft or the like. Where it is desirable to provide for the dropping ofV a plu rality of 'bombs in predetermined timed sequence, at relatively brief time intervals apart, the present invention provides a highly satisfactory control for this purpose, which is highly simple in construction and omration, and which involves only a low weight and substantial freedom from coliE plexity in operating mechanism. It provides for errample for the dropping of bombs at a predetermined desired rate such for example at rates varying from two per second to twenty per second under simple manual control on the part of the operator; and such limits and range of speeds may be subject to sumtantial variation as desired. it further provides for the preselection by the operator of a predetermined number of impulses to .be generated, and hence of a predeter mined number of bornes to be dropped, follow mg which the device ceases its functioning, while providing visual indication to the operator at all.

times of the number ci operations completed and remaining to be completed. The device also preferabiy incorporates a manual control by means of which operator may individually eifect the release of the combs when that operation is de'- aired. While not limited to the utilization of the periodic timed impulses for the releasing of bombs, that function forms a preferred lield of application for the device, and will be referred to hereinciter in connection with the detailed description of the operation of the mechanism.

Referring to Fig. 1 of the drawings, this figure shows diagrammatically a simple timing circuit for securing the alternate operation of a plurality of relays i t and it, in timed relation one with the other. a source of electrical energy is shown at i3 as comprising a battery, such as utilized upon an aircraft, though other suitable sources of direct current potential may likewise 'be utilized.

One side of the power source shown as the negative is connected through a condenser it with each of the energizing coils ita and l2@ of the two relays i@ and it. The relays have armatures lub and ith each of which carries a pair of contact arms lilo, idd and 92o, iid. Fixed contacts jue and |29 are arranged to .be closed -by switch arms itc and iic respectively upon the actuation of the relays, while switch contacts wf and idf are arranged to be closed by switch arms ld and ltd respectively upon deenereization and release o1" the respective relays. Retractile springs its and iig cause the return of the armatures and associated switch arms to the non-actuated position upon the deenergization of the respective relays, to positively open contacts itc, lic and ite, ire, andto cause the ,closing of contacts id, illy and iid, tif.

The energizing circuit through coil ita is complated through contacts ttf, iid of relay i2 so that relay i@ may be energized only when relay it? is deenergized. Similarly the energizing circuit for coil 52a is completed through contacts if and ltd of relay i@ so that relay i2 may be energized muy during the time that the relay lo is deenergized.

'I'hus the circuit for relay I0 includes condenser I4, coil Illa, contacts I2f and I 2d, manual control switch I5, and back to the positive side of the power source I3. And upon closing of switch l5 current flow takes place to cause the building up of a charge upon condenser I4. The rate of such flow of charging current will vary with the actual values -of capacitance and resistance in the circuit, beginning at a high value and progressively decreasing in amount as the charge on the condenser builds up.

Contacts I0c and I0e upon closing establish a shunt circuit around the coil I 0a of relay I0 which includesa variable resistor I6 through which Va portion of the charging current flowing through condenser I4 may pass following actuation of the relay. Similarly contacts I2C and I2e upon closing establish a shunt circuit around the coil I2a which includes variable resistor I1 through which a portion of the current passing through vcondenser I4 may pass.

The operation of this device is as follows. Upon the closing of manual switch I5, and with both relays deenergized, an energizing circuit for relay I0 is established through condenser I 4, coil I0a, switch contacts I2f, I2d, through switch I5, and back to the opposite side of the power source. A circuit is also closed through coilI2a, but since there is no difference of potential in this circuit, relay I2 does not operate. A maximum ilow of current takes place through the circuit of relay IU as described, beginning the charging of condenser I4, this flow resulting in the operation of relay I0 to strongly attract armature IIlb, thereby closing contacts Illc, Ie, and opening contacts Illd and If. The opening of the latter contacts opens the circuit through relay I2, and makes it impossible for that relay to be actuated` 'I'he closing of contacts IIlc, Ille establishes the shunt circuit around the coil Illa including variable resistor I6. The effect of thus placing a resistor in parallel with the coil Illa is to reduce the effective resistance in the charging circuit of con-V denser I4, thereby reducing the time required for the building up of the charge within the condenser. As the charge increases, the flow of current will decrease, and ultimately reach a point at which there is insufficient current now to maintain the relay in actuated condition. When such point is reached relay I0 releases, opening contact |00, Ille, and closing contacts Id, IIlf. The latter establishes a circuit through coil I2a and the now charged condenser I4. The condenser immediately begins to discharge at a maximum rate, resulting in actuation of relay I2, thereby opening the circuit through coil Illa at contacts I2f, I2d,. and closing the shunt circuit through resistor I1 at contacts I2c, I2e. Thus as soon as the relay has been actuated, the shunt circuit for controlling the time required for the discharge of the condenser is established, and the relay remains energized as long as thre is a suflicient ilow of discharging current. When the value of the discharge current falls below a predetermined point, it is no longer sulcient to maintain relay I2 in actuated condition, and this relay then releases, again establishing the charging circuit through relay I0. Such operations thereafter continue as described and because the periods of time between successive operations are dependent upon the electrical characteristics of capacitance and resistance, they are subject to predetermined control and are maintained with considerable accuracy as so selected.

GII

In order to effect regulation of the period during which the relays remain energized, and hence controlling the time intervals between actuation of the two relays, resistors I6 and I1 may be properly adjusted. Upon increasing the values thereof, up to the maximum point where the shunt circuit would be entirely open. it will be apparent that the characteristics of the charging and discharging circuits will be determined by the values of capacity of the condenser, and the xed resistance in the circuit, primarily that of the relay coils themselves; and that under such circumstances the maximum time to eil( ,t charging and discharging will be required vhence resulting in longer time intervals between operations. If desired, it will be clear that additional resistance can be inserted in series with the condenser to further extend the time required for charging and discharging thereof.

On the other hand when 'the values of resistance are decreased to the minimum which represents a short circuit around the respective relay coils, which however is notestablished until after the completion of actuation thereof, it will he clear that the minimum time will be required thereafter to complete the charging or discharging of the condenser, since the charging resistance has been substantially eliminated, and hence this results in producing shorter time intervals between operations.

It will also be clear that the actual period necessary for these operations will vary with the capacitance of condenser I4, and that this may be varied as well as the resistance in the charging circuit, to secure a variable time of actuation. Using very large values of capacity discharging through small resistances at a high rate results in high currents and consequent probability of deterioration of the contacts. Likewise an amount of internal resistance in the condenser comparable with the resistance of the charging or discharging circuit may cause faulty operation so that it is generally found desirable, in attaining the higher operating speeds, to reduce the capacity of the timing condenser rather than by the use of a very low adjusting resistor. This is readily accomplished by the use of a plurality of electrolytic condensers arranged to be selectively included in the circuit, the use of such condensers being desirable in view of their relatively large capacity and small space requirements. However because it is usually not practicable to secure extreme accuracy in the capacity of such con- -densers, the concurrent use of adjustable resistors has also been found desirable.

It will thus be observed that each relay, assuming it to have similar electrical and physical characteristics, will require substantially the same length of time to actually close following initiation of flow of the charging or discharging current, and will be maintained in actuated condition by substantially the same rate of current flow through the two coils. Thus there is a constant factor in the timing period represented by that time required for the release of one relay and the operation of the other: and a variable factor representing the time during which each of the relays remains in its actuated condition. This latter factor is subject to variation and control as described above, and may be made relatively short in proportion to the ilrst factor such as an interval corresponding approximately with or even less than the time required for the mechanlcal movements, or may be made substan- A 2,347,481 tially longer than this period, for example up? to?? the" two yariableiresismrs; s e', n, jwhiciisipgieref isplacd in'circitwithboththe charging f i Such amarrangement-is show n diagrammati` riaiiyinr'ig; 2fin1wmch1therelgys'in' and l2 are each 'providedas described ,above rwith thea'ctuat'ing coils. ,and other parts Illu to Ig and. I2a to, I 2gy respectively. 'However inplace of the separateresstors Il52,.l`i, a single resistor 2t is pro- "vide'd, madesuitably variable', and connected to be`placed' inshunt circuit with the respective relay coils a/and' I2i so las to be alternately incx'nprated in fthe, charging and the discharging circuits 4 of. condense rs I following actuation ofthe respectiverelays.y Variation oi this resistor produceslvariation inthe lengthv of Itime lduring which the flow of Acharging current or discharging current continues in excess of that minimum value required to maintain the relay armature'in actuated condition, -and hence provides 'for regulating jthe'period of actuation and the frequency fof 'operation in the same manner as resistors I6," I l described above.

' FurthermoreFig. `2 showsyadditional contacts tiene@nidftfonwiihresecwininhet ingle' fesistsrmay ,beyincorpbirated'mance' ,or

'discharging jcirgintetp give sinner' .co resistance charactesticstherein, and

I tion Oil-,119W Ofrcharging and -d' vdischarging current from the charged condenser i the frequency 0f .ever t9e;d f. f.sa,c1 relayswlll. salam-.a@freestanding ha ;I ,e une .tiene f ations of solenoid. 2

9,. doubled; iflared- It will alsobe apparent that,

eectual. @uw

, arginscurrent in the circuit of 'solenoid 2 2.may3 beQmade-.indeej pendent Lof'` the contacts {0d} 'Ilm-and I2d, I2); when condenser. 23v included in' lthe circuit` Thus bysqitame seiejctionjpf the electrical hafacteri'stics, i. e., capacitanceandresistance, inthe circuit of solenoid 22,-th chargingand discharging currents may beso regulated fasjto-.havedecreased 'toa substantially@lowwalue at the time of opening ofthe respective switch contacts in the circuit; as a result thereforearing andin'-, jury to the contact points may be reduced toa minimum. Further it Iwill be alsoclear that where it is desired to effect the actuation of an 4Iilt and 'I2h arranged to be closed respectivelyV by contact arms `I @0d and I2d upon actuation of the respectiv'relays l and I2, i These contacts Considering iirst` the caseavhere switch 24 is closed, andhence condenser 23 removed from the crcuitof solenoid 22, it will be apparent that upon actuation of relay IB, closing contacts Illd and Ilm, a circuit is completed through the power source, said contacts, solenoid 22,. closed switch 26, and baci: to the other side of the power source. As va result thereof current flows through solenoid-22,-r producing a timed electrical impulse for ,eectinfg a control operation as desired. Upon the. release of relay Ill, and the subsequent actuation `of relay I2, it will be seenthat the power source is no `longer included in the circuit of solenoid 22, and hence no energization of thesolenoid takes place upon actuation of relay I2.

Consequently, a timed actuation of solenoid 22 occurs once for each operation oirelay II),l with no`corresponding energization upon operationI of However ywhen switch ,726. ,is open thereby in'- ing ,contacts vI2d y and,` i211., a; discharging circuit is established through said contacts, and thesole- .incid )22, ,through which there --Qccurs 'a flower auxiliary device underthe control 'ofi solenoid 22,

particularlywhere such device has parts requiring any material period of time `for resetting after one actuation in preparation for the next, this circuit provides for a strong timed operating pulse through solenoid 22, which can thenbe .termi-y nated promptly, by reason of the substantial completion of flow of charging or discharging current, affording the mechanism ample time for resetting, prior to thev subsequent operationof the other relay and the generation of a subsequent operatingpulse through the solenoid. Hence, the beginning of yeach timed pulse is accurately com trolled, but the solenoid is not unnecessarily maintained in energized condition during the time interval that the timing relays continue to be energized. By terminating the ow of,l current through the solenoid in a lesser 'period'of'- time, the mechanism controlled thereby is given ade,- quate time for resetting, and damage to the switch points is substantiallyy eliminated.

Where an odd number of impulsesris desired, that is where theoperation terminates with the energization of relay I0, it is clear that a charge might be left upon condenser 23, and if not dissi-` pated, would `interfere vwith the' beginning of a subsequent cycle of operations, delaying thoselop erations by a half cycle. Accordingly it is'preI ferred to place a high resistance 25 across condenser 23 through which anyl Aresidual charge thereon can be dissipated, but which is of such high resistance as to not materially alter the characteristics of the 'system duringnormal operation.

F g. 3 shows the application of ,the present invention to an arrangementiorf dropping bombs in predetermined timed.'= sequence.` The relay parts and switch convtactvs'l to )Ihfand I2 to I2h are as described abova'and are similarly identied for easy rference. order toI secure .pref determined` timed operation ofthe device ata rate Ato be manually selected, a plurality. of conder isers I 4a. I 4b Aand No areutilzed.'.f Lilewise atapped resistor 20 'is arranged to befincorporated `,in the charging and, discharging circuitsy otysaid condensers inthe mannerof relayf2ll describedabove. A manual4 control switch 3l)y isuprovided comprising an indicating dialllaI upon v4which the 4speeds vare show mandy three switch arms 30h-,300, Vand 30d, preferably arranged in. separate planes or decks and actuated by a common shaft indicated at 30e. The switches have a series of positions shown as eleven in number, corresponding to the indicated speeds on the dial 39a, a representative series of such speeds being 2, 3, 4, 5, 6, 8, 10, 12, 14, 16 and 20 operations per second. In order to secure such variable range of operations, these switches are made to selectively control the incorporation of the several condensers and variable resistors in circuit as will be ldescribed more in detail hereinafter.

The bomb rack is shown diagrammatically at 35, comprising a series of release arms 36 having depending fingers 31 upon which the bombs 38 are retained. A compression spring 38 acting against a collar 40 fastened to the arms 36 normally tends to withdraw said arms and to eect the release of the bomb. However a cam plate 4I is arranged in line with each of the arms 36, and has a cam face 42 thereon of varying length, which normally engages the arms 36 and prevents their movement to release the respective bombs. Cam -plate4l is provided with ratchet teeth 43, and apivotally mounted pawl member 44 is arranged to engage said teeth to eiect the notching of the cam` plate upwardly. Operation of the pawl 44 is effected electrically by means of a solenoid 45, cach actuation of which causes the pawl to lift the cam plate by one notch. As shown the severalffaces 42 'are such that the lowermost arm 36 will be released upon the first actuation of pawl 44, and since the face in contact with the next uppermost arm 36 is proportionately wider,

it will be released upon the second pawl operation.

Similarly each lsuccessively higher bomb will be caused to be released upon each additional pawl operation. It will be understood that other suitable mechanism for effecting sequential operatons of the character described, upon a series of energizations of solenoid 45, may be utilized as desired.

In some cases it may be desired by the operator to secure complete manual control of the release of the bombs, and in others to secure the timed sequence operation as described herein. To provide4 for securing such selective operations, a double-pole, double-throw control switch 48 is provided which when thrown to one position as shown to the left, provides for securing timed sequential operation, and when thrown to the right provides for individual control of the operations by manual means. The description will beI directed primarily to the former type of operation with the switch 48 thrown to the left to establish the predetermined and timed sequential operation of the system.

In order that the operator may manually control the operations of the system and also receive an indication of the exact status of the operation at any time, a manually controlled preselector device 50 is provided having an indicating dial 50a upon which are indicated the total number of operations to be performed, for example the total number of bombs held in the rack. A manually adjustable pointer arm 50h is arranged for cooperation with such scale, and upon manual operation, is adapted' to effect rotation of a shaft 50c. This shaft carries al cam disk 50d having a cam pin 50e thereon which is arranged to eiect the opening of a limit switch 52 when the desired numbe'r of operations have been completed. The

pin 50e is related to the indicating arm 50h in such manner that when arm 50h stands vat the zero or off position, switch 52 is open but at any voperative positionv at'which arm 50h may be set',

switch 52 is closed.

The shaft likewise carries a toothed wheel 50f with which there engages a notching pawl 54 and a non-reverse pawl 55. A solenoid 66, corresponding in function and operation with solenoid 22 as described above in connection with Fig. 2, is provided with armature 56a, which carries switch arms 56h and 56e. The armature likewise is connected to the pivoted pawl member 54 so that upon each actuation of solenoid 56 the pawl is actuated, and the toothed wheel is advanced one step.

pon adjustment of the preselector device 50 to move the indicating hand away from the ot! position, limit switch 52 closes, and a circuit for an indicating light 60 is closed, indicating to the operator that the system is preconditioned for operation. The arm 50h is adjusted to a position corresponding to the number of operations which it is desired to secure, and as will be clear the adjustment of this arm'to a proper indicating value on the dial will indicate the number of operations which will take place before the limit pin 50e opens the limit switch 52.

With the preselector device thus adjusted, and the indicator device 60 operated, the operator may depress a manual push button 6| which closes an energizing circuit through hold-in relay 62, such circuit being completed through the closed contacts of limit switch 52. Upon operation relay 62 closes its contact arm 62a upon contact 62h, and thereby establishes a holding circuit around push button switch 6I so that the latter may be released after its initial operation. Relay 62 also carries a switch arm 62e which closes upon contact 62d, thereby closing a circuit from one side of the power source through switch contacts 10d, lllh, or I2d, I2h, through the switch 48, and to one side of relay 56, which in turn is connected to the opposite side of the line by one of the arms of switch 30, and back to the opposite side of the power source either directly or through one of the doubling condensers I4b or |4c, depending upon the setting of switch 30. Accordingly energization of solenoid 66 occurs,

' in denite timed relation with the operation of relays l0 and I2. Upon each operation of relay 56, switch arm 56h closes contact 56d, and connects the operating solenoid with the power source so as to secure the release of a bomb.

In order to avoid unnecessary arcing of the contacts 56h and 56d, an arc-suppressing condenser 51 is connected across such contacts to avoid objectionable arcing therein. Likewise upon operation relay 56 closes switch arm 56e upon contact 56e, the latter establishing a shunt circuit around the contacts ld, Illb and I2d, I2h so that assurance will be provided that the last operation will be certain of being completed, regardless of the exact point in the cycle at which the limit switch 52 opens.

Operation of relay 56 continues in predetermined timed sequence under the control of the relays I0 and I2, each operation effecting the notching of the preselector device by anotherv step. Finally when the predetermined number of operations has been completed, as determined by the initial setting of control arm 50h, limit pin 50e engages the movable contact of the limit switch 52, thereby opening the circuit through the controlrelay 62 and extinguishing the indieating light and deenergizing both relays l0 and l2. As above described however the last cycle of operation is continued through contacts electromagnetic relay means, a circuit 'for Ieach said relay including control contacts actuated by the other relay and arranged to be closed only upon deenergization of said other relay, a

condenser, connections for establishing a charg ing circuit for said condenser through one of said relays toeiect actuation thereof, said relay being maintained in'actuated condition during continuance of the ow of charging current in,excess of a predetermined value, and connections effective upon release of said relay for establishing a circuit for the other of said relays for the discharge of said condenser, said other relay being maintained in actuated condition during continuance of the iiow of said discharge current in excess of a predetermined value, means adapted to be placed in circuit with said relay and said condenser for varying the time required for the charging current and discharging current of said condenser to fall be,- low said predetermined minimum value to thereby vary the length of time during which each of said relays remains energized, and means for excluding said time varying means from the charging and discharging circuits for said relays until after initial actuation thereof and for then including said time varying means in said circuits to provide for said timing control while assuring positive actuation of said relays.

3. A timing device of the character described adapted to be energized from a source of electrical energy and to establish predetermined uniform time intervals comprising a plurality of electromagnetic relay means, a circuit for each said relay including control contacts actuated by the other relay and arranged to be closed only upon deenergization of said other relay, a timing condenser, connections for establishing a charging circuit for said condenser through one of said relays to effect actuation thereof, said relay being maintained in actuated condition during continuance of the ow of charging current in excess of a predetermined value, and connections effective upon release of said relay for establishing a circuit for the other of said relays for the discharge of said condenser, said other relay being maintained in actuated condition during continuance of the ilow of said discharge current in excess of a predetermined value, a single resistance means for controlling the time required for the charging and discharging of said condenser, and means for conn ecting said same resistance means in circuit with said condenser and said relays alternately upon the actuation thereof to thereby vary the length of time required for the current through said relay to fall below said predetermined minimum Value with resultant release thereof.

4. A timing device of the character described for controlling the lperiodic dropping of bombs and the like 'adapted to be energized from a source of electrical venergy and to establish predetermined uniform time intervals comprising a plurality of electromagnetic relay means, a circuit for each said relay including control contacts actuated by the other relay and arranged to be closed only upon deenergization of said other relay, a timing condenser, connections for establishing a charging circuit for said condenser through one of said relays to eiect actuation thereof, said relay being maintained in actuated condition during continuance of the iiow of charging current in excess of a predetermined value, and connections eiective upon release of said relay for establishing a circuit for the other of said relays for' the discharge of said condenser,

said other relay being maintained in actuated condition during continuance of the ow of said discharge current in excess of a predetermined value, means for varying the' time required for vthe charging and discharging currents to fall below said predetermined minirmun including means for varying the capacitance-resistance characteristics of the circuit, and means for including the same time varying means in circuit with one and then the other of said relays im- Inediately` following the actuation thereof in order to provide said timing control with positive actuation thereof.

5. A timing device of the character described adapted to be energized from a source of electrical energy and to establish periodic timed impulses which comprises a plurality of relay means each.having circuit control means associated therewith, a condenser. circuit connections providing for establishing a charging circuit for said condenser for one of said relays to eiect actuation thereof vwhile the other relay remains deenergized, said rst relay remaining energized While the flow of charging current therethrough exceeds a predetermined value, circuit connections effective upon release of said rst relay for establishing a circuit through said second relay for the discharge of said charged condenser, said second relay remaining energized while the ow of discharging current therethrough exceeds a predetermined value, thereby securing alternate timed operation of said relays, and means associated with said charging and discharging circuits for varying the capacityresistance characteristics thereof to predetermine the length of time required in said charging and discharging operations, a single control circuit, and switch means operated by said relays for effecting periodic alternate introduction of said single control circuit into the circuit of said rst and second relays.

6. A timing device of the character described adapted to be energized from a source of electrical energy and to establish periodic timed impulses which comprises a plurality of relay means each having circuit control means associated therewith, a timing condenser, circuit connections providing for establishing a charging circuit for said condenser through one of said relays to eiect actuation thereof while the other relay remains deenergized, said rst relay remaining energized while the flow of charging current therethrough exceeds a predetermined value, circuit connections effective upon release of said rst relay for establishing a circuit through said second relay for the discharge of said charged condenser, said second relay remaining energized While the flow of discharging current therethrough exceeds a predetermined value, thereby securing alternate timed operation of said relays, and means associated with said charging and discharging circuits for varying the capacity-resistance characteristics thereof to predetermine the length of time required in said charging and discharging operations, a control circuit, a solenoid in the control circuit, a multiplying condenser in circuit with said solenoid and adapted to be charged from the source of electric energy, switch contacts operated by said relay means for eiecting closing of a charging circuit through said solenoid and said multiplying condenser, and switch means carried by the other of said relay means for closing a discharge circuit of said multiplying condenser through said solenoid to eect ed actuation thereof upon actuation of each of said relays. y

7. A timing device of the character described adapted to be energized from a source of electrical energy and to establish periodic timed impulses which comprises a plurality of relay means each having, circuit control means associated therewith, a timing condenser, circuit connections providing for establishing a charging circuit for said condenser through one of said relays to eect actuation thereof while the other relay remains deenergized, said rst relay remaining energized while the :dow of charging current therethrough exceeds a predetermined value, circuit connections e'ective upon a release of said first relay for establishing a circuit through said second relay for the discharge of said charged condenser, said second relay reymanning energized while the flow of discharging current therethrough exceeds a predetermined value, thereby securing alternate timed operation of said relays, and means associated with said charging and discharging circuits for varying the capacity-resistance characteristics thereof to predetermine vthe length of time requiredl in said charging and discharging operations, a control circuit, a solenoid in the control circuit, a multiplying condenser in circuit with said solenoid and adapted to be charged from the source of electric energy, switch contacts carried by said relay means for eecting closing of a charging circuit through said solenoid and said condenser, and switch means operated by the other of said relay means for closing a discharge circuit of said multiplying condenser through said solenoid to edect actuation thereof upon actuation of each of said relays, and control means for removing said multiplying condenser irom the solenoid circuit to provide for actuation thereof in' response to operation of only one of said relays.

8. A timing device of the character described adapted to be energized from a source of electrical energy and to establish'perodic timed impulses which comprises a plurality oi relay means each having circuit control means asso? 'elated therewith, a timing condenser, circuit connections providing for establishing a charging circuit for said condenser through one of said relays to eiect actuation thereof While the other relay remains deenergized, said rst relay remaining energized while the dow of charging current therethrough exceeds a predetermined value, circuit connections effective upon a release of said iirst relay for establishing a circuit through said second relay ior the discharge of said charged condenser, said second relay remaining energized While the ilovv of discharging current therethrough exceeds a predetermined value, thereby securing alternate timed operation of .said relays, and means associated with said charging and discharging circuits for varying the capacity-resistance characteristics thereof to predetermine the length of time required in said charging and discharging operations, a control circuit, a solenoid in the control circuit, a multiplying condenser in circuit with said solenoid and adapted to be charged from the source of electric energyVswitchcontacts carried by said relay means for effecting closing of a charging circuit through said solenoid and said condenser, and switch means operated by the other of said relay means for closing a discharge circuit of said multiplying condenser through accuser Y i i operations.

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said solenoid to euect actuation thereof upon actuation of each ci said relays, the flow of current through said solenoid during charging and discharging of said condenser being maintained for a period of the order of or less than the period during which said relays remain in actuated condition.

9. A timing device, of the character described adapted to be energized from a source of electrical energy and to establish periodic timed impulses for ,controlling the dropping of bombs and the like which comprises a plurality of relay means each having circuit control means associated therewith, a condenser, circuit connections providing for establishing a charging circuit for said condenser through one of said relays to eect actuation thereof while the other relay remains deenergized, said iirst relay remaining energized while the new of charging current therethrough exceeds a predetermined value, circuit connections effective upon release of said first relay for establishing a circuitV through said second relay for the discharge of said charged condenser, said second relay remaining energized while the flow of discharging current therethrough exceeds a predetermined value, thereby securing alternate timed opera- .tion of said relays, means associated with said charging and discharging circuits forV varying the capacity-resistance characteristics thereof to predetermine the length of time required in said charging and discharging operations, a control circuit, a solenoid in said control circuit adapted to be repeatedly energized at uniform intervals corresponding to the timed operation of said relays, counter-mechanism actuated by said solenoid at each energization thereof to count the number of such actuations, and means controlled by said counter mechanism for eecting the opening of said relay circuits to terminate the operation of said relays after completion of a predetermined number of such l0. A timing device of the character described adapted to be energized froma source of electrical energy and to establish periodic timed im pulses for controlling the dropping of bombs and the like which comprises a plurality of relay means each having circuit control means associated therewith, a condenser, circuit connections providing ior establishing a charging circuit for said condenser through one of said re lays to eiect actuation thereof While the other relay remains deenergized, said irst relay remaining energized while thel flow of charging current therethrough exceeds a predetermined value, circuit connections eiective upon release of said first 'relay for establishing a circuit through said second relay for the discharge of said charged condenser, said second relay remaining energized while the iloW of discharging current therethrough exceeds a predetermined value, thereby securing alternate timed operation of said relays, means associated with said charging and discharging circuits for varying the capacity-resistance chars cteristics thereof to 'predetermine the length of time required insaidvcharging and discharging operations, a control circuit, a solenoid in said control circuit adapted to be repeatedly energized at uni form intervals corresponding to the timed operation of said relays, counter-mechanism actuated by said solenoid at each energization thereof to count the number of such actuations, means operable'to eiect deenergization of said relays fwhen said solenoid has been 'actuated a pre- Idetermined number of times, and additional circuit control means to assure completion of each actuation of said counter mechanism including the last actuation thereof.

' 11. A timing device of the charactery described adapted to be energized from a source of electrical energy and to establish periodic timed impulses for controlling the dropping of bombs and the like whichicomprises a plurality of relay means each having circuit control means associated therewith, a condenser, circuit connections providing for establishing a charging circuit for said condenser through one of said relays to eiect actuation thereof while the other relay remains deenergized, said first relay remaining energized while the iiow of charging until the return of said counter mechanism to current therethrough exceeds a predetermined value, circuit connections eiective upon release of said first relay for establishing a circuit through said second relay for the discharge of said charged condenser, said second relay remaining energized while the flow of discharging current therethrough exceeds a predetermined value, thereby securing alternate timed operation of said relays, means associated with said charging and discharging circuits for varying the capacity-resistance characteristics thereof to predetermine the length of time required in said charging and discharging operations, a control circuit, a solenoid in said control circuit adapted to be repeatedly energized at uniform intervals corresponding to the timed operation of said relays, counter-mechanism actuated by said solenoid at each energization thereof to count the number of such actuations, limit switch means actuable after a predetermined number of operations of said solenoid to deenergize said relays, manually operable means for setting said limit switch to a position corresponding to a desired number of operations indicative of the number of bombs to be dropped,

its said zero position.

14. A timing device for use in the sequential dropping of bombs and the like comprising a timing circuit adapted upon being energized to produce a series of periodic impulses of preselected variable frequency uniformly commencing immediately following such energization, counter mechanism having a zero position and a series of operative positions corresponding to the desired number of bombs to be dropped, means for effecting step by step operation of said counter mechanism from-any of its said operative positions to its zero position in response to said periodic impulses, a limit switch in the timing circuit actuated by said counter mechanism selectively in relation to the position of said mechanism in its said operative or in its said zero position, means controlled by said limit switch means and adapted to be actuated upon adjustment of said counter and means operable only after said manuallyoperable means has been set to a predetermined operative position for indicating that said device is preconditioned for operation.

12. A timing device for use in the sequential dropping of bombs and the like comprising a timing circuit adapted upon being energized to produce a series of periodic impulses of preselected variable frequency at uniform intervals following such energization, a counter mechanism adapted to be set for a predetermined number of operations, means for actuating said counter mechanism at each of said periodic impulses, means controlled by the operation of the counter mechanism for opening and disabling the timing circuit following said predetermined number of actuations thereof, and means for by-passing said circuit opening means during the operating movement of said counter mechanism to assure completion of each actuation thereof including the last actuation.

13. A timing device for use in the sequential dropping of bombs and the like comprising a timing circuit adapted upon being energized to produce a series of periodic impulses of preselected variable frequency uniformly commencing immediately following such energization, counter mechanism having a zero position and a series of operative positions corresponding to the desired number of bombs to be dropped, means for effecting step by step operation of said counter mechanism from any of its said operative mechanism to any of its operative positions to effect control of an indicator showing said device to be preconditioned for operation, and circuit control means under manual control for closing the circuit through said limit switch to energize and initiate operation of said timing circuit until the desired predetermined number of operations have been completed, said circuit being maintained through said limit switch until the return of said counter mechanism to its said zero position.

15. A timing device for use in the sequential dropping of bombs and the like comprising a y timing circuit adapted upon being energized to produce a series of periodic impulses of 'preselected variable frequency uniformly commencing immediately following such energization, counter mechanism having a zero position and a series of operative positions corresponding to the desired number of bombs to be dropped, means for effecting step by step operation of said counter mechanism from any of its said operative positions to its zero position in response to said periodic impulses, a limit switch in the timing circuit actuated by said counter mechanism selectively in relation to the position of said mechanism in its said operative or in its v`manual control for closing the circuit through said limit switch to energize and initiate operation of said timing circuit to produce said timed impulses, means for maintaining said limit switch circuit closed until the desired predetermined number of operations have been completed, said circuit being maintained through said limit switch until the return of said counter mechanism to its said zero position, and a selector switch operable to disable said maintaining means to provide for individual. control of said operations by said manual control.

FREDERICK J. HOOVEN. 

